#ifndef DLIST_H
#define DLIST_H

#include <stdlib.h>

/* Define a structure for doubly-linked list elements */
typedef struct DListElmt_ {
  
  void *data;
  struct DListElmt_ *prev;
  struct DListElmt_ *next;
  
} DListElmt;

/* Define a structure for doubly-linked lists */
typedef struct DList_ {

  int size;
  int (*match)(const void *key1, const void *key2);
  void (*destroy)(void *data);
  DListElmt *head;
  DListElmt *tail;
  
} DList;

/* Public Interface */
void dlist_init(DList *list, void (*destroy)(void *data));

void dlist_destroy(DList *list);

int dlist_ins_next(DList *list, DListElmt *element, const void *data);

int dlist_ins_prev(DList *list, DListElmt *element, const void *data);

int dlist_remove(DList *list, DListElmt *element, void **data);

#define dlist_size(list) ((list)->size)

#define dlist_head(list)  ((list)->head)

#define dlist_tail(list)  ((list)->tail)

#define dlist_is_head(element)  (NULL == (element)->prev ? 1 : 0)

#define dlist_is_tail(element)  (NULL == (element)->next ? 1 : 0)

#define dlist_data(element)  ((element)->data)

#define dlist_next(element)  ((element)->next)

#define dlist_prev(element)  ((element)->prev)

#endif
